JPH0457876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vane compressor used in vehicle air conditioners and the like.

(Prior art and its problems) As is well known, a vane compressor includes a cam ring whose both sides are closed with side blocks, a rotor rotatably disposed within the cam ring, and a vane groove in the rotor. A vane is fitted so as to be retractable and whose tip can slide against the inner circumferential surface of the cam ring. It compresses the fluid introduced into the compression chamber.

In this type of vane compressor, the compression start position is changed by adjusting the intake amount of compressed gas,
A variety of so-called variable displacement vane compressors have been proposed that allow the compressor capacity to be controlled by realizing a full operating state where the discharge capacity is maximum and a partial operating state where the discharge capacity is reduced. has been done.

However, in the conventionally proposed variable capacity vane type compressor, the suction amount adjustment mechanism for compressed gas is complicated, which is a factor in increasing costs.

(Object of the Invention) The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a variable capacity vane type compressor that has a simple structure and can be manufactured at low cost.

(Means for Solving the Problems) In order to achieve the above object, the vane type compressor according to the present invention includes a cam ring whose both sides are closed with side blocks, and a cam ring rotatably disposed within the cam ring. A rotor and a plurality of vanes that are slidably fitted into vane grooves of the rotor, and the suction chamber is compressed through a suction port by a change in volume of a compression chamber defined by the side block, the rotor, and the vanes. In a vane type compressor configured to compress fluid introduced into the compression chamber from a compressor, a compressor is provided downstream of the suction port of the one side block in which the suction port is provided, and the suction chamber and the compression chamber are connected to each other. a bypass port that communicates with the vane base, and a back pressure receiving chamber into which the back pressure applied to the vane base is introduced. an opening/closing means that is biased in a direction to open the bypass port, an opening/closing valve that opens and closes a communication passage that communicates the back pressure receiving chamber and the suction chamber, and when the pressure of the suction chamber is below a predetermined value; By opening the on-off valve, the pressure in the back pressure receiving chamber is lowered to below the spring force, and when the pressure in the suction chamber is above the predetermined value, opening the on-off valve reduces the back pressure. The present invention is characterized by comprising a control means for increasing the pressure in the pressure receiving chamber to a level higher than the spring force.

(Example) Hereinafter, each example of the present invention will be described with reference to the accompanying drawings.

1 to 5 show a vane type compressor according to a first embodiment of the present invention. In the figure, the housing 1 of this compressor consists of a bottomed cylindrical case 2 with an open end, and a front head 4 attached to one end of the case 2 with bolts 3 so as to close the open end. Become.

A gas discharge port 5 as a heat medium is provided on the upper surface of the case 2, and a gas inlet port 6 is provided on the upper surface of the front head 4.

A compressor main body 7 is housed inside the housing 1 . The compressor main body 7 includes a cam ring 8
and front side blocks 9 mounted on both open ends of the cam ring 8 so as to close the opening surfaces.
The main components are a rear side block 10, a rotor 11 rotatably housed inside the cam ring 8, and a rotating shaft 12 of the rotor 11, which is connected to both side blocks 9, 10.
It is rotatably supported by respective bearings 13 and 14 provided in the.

The inner peripheral surface of the cam ring 8 has an elliptical shape as shown in FIG.
Therefore, between the inner circumferential surface on the long axis side of the cam ring 8 and the outer circumferential surface of the rotor 11, there are compression chambers 1 at 180 degrees symmetrical positions.
5 and 15 will be defined.

The rotor 11 has a vane groove 16 along the radial direction.
A plurality of vanes (for example, four) are provided at equal intervals in the circumferential direction, and vanes 17 are provided in these vane grooves 16.
is movable in the radial direction, and its tip is slidably fitted into the inner circumferential surface of the cam ring 8. A back pressure chamber 18 is defined between the bottom of each vane groove 16 and the base end of the vane 17, and lubricating oil is pumped into this back pressure chamber 18. The significant back pressure exerted in the back pressure chamber 18 causes the vane 17 to easily pop out from the vane groove 16, and the tip of the vane 15 to be attached to the cam ring 8.
An appropriate value that does not cause excessive sliding resistance when sliding against the inner circumferential surface, for example, 1/1/2 of the sum of the discharge pressure and suction pressure.
As is well known, the pressure is set to 2 (ie, intermediate pressure).

As shown in FIG. 3, the side block 9 is provided with suction ports 19, 19 at 180 degree symmetrical positions. A suction chamber 20 between the front head 4 and the front side block 9 and the compression chamber 15 communicate with each other through the suction ports 19, 19. Furthermore, this side block 9 has a bypass port 2 on the downstream side of the suction ports 19, 19.
1 and 21 are provided at 180 degree symmetrical positions. These bypass ports 21, 21 are the suction port 1.
Similar to 9 and 19, the suction chamber 20 and the compression chamber 15 are communicated with each other.

The bypass ports 21, 21 are piston valves 2
Opening/closing is controlled by 2. Figure 1 shows piston valve 2
2 shows a closed state (upper side) and an open state (lower side) of the bypass port 21, respectively. As shown in FIGS. 1 and 2, the piston valve 22 includes a piston movable portion 23 that is slidably supported in the front head 4 at the inner bottom of the suction chamber 20 in the axial direction of the rotor 11, and a piston movable portion 23. 23
An arm 24 stands upright at one end of the side block 9 of the
The bypass ports 21, 21 are provided protrudingly from both ends of the
It consists of port valves 25, 25 that are in sliding contact with a part of the inner peripheral surface. Bypass port 21, 21 is compression chamber 1
Small diameter holes are formed on the 5 and 15 sides, and large diameter holes are formed on the suction chamber 20 side. The port valves 25, 25 move forward and backward in sliding contact with a part of the inner periphery of the large diameter hole, and open and close the small diameter hole whose tip forms a valve seat. And port valve 2
5 and 25 retreat toward the suction chamber 20 to open the small diameter hole, the suction chamber 20 and compression chambers 15 and 15 communicate with each other through the large diameter hole.

The port valves 25, 25 are always urged toward the suction chamber 20 by a corrugated leaf spring 26. The corrugated plate spring 26 is formed into a ring shape, and its inner peripheral end is held between the front side block 9 and the front head 4, and its outer peripheral end is engaged with the side peripheral surfaces of the port valves 25, 25.

A back pressure receiving chamber 27 is provided at the sliding contact portion on the other end side of the piston movable portion 23 . This back pressure receiving chamber 27 communicates with the back pressure chamber 18 via a communication passage 28.

On the other hand, as shown in FIG. 4, the front side block 9 is provided with a ball valve 29 as an on-off valve. This ball valve 29 consists of a coil spring 30 disposed in a valve chamber and a ball 31 urged by the coil spring 30 to close the valve seat. The valve chamber of the ball valve 29 communicates with the back pressure chamber 18 via a communication passage 32, and the valve seat of the ball valve 29 communicates with the suction chamber 20 via a communication passage 33. The front head 4 is provided with a pressure-responsive body, such as a bellows 34, as a control means for controlling the opening and closing of the ball valve 29. The bellows 34 expands and contracts via the communication passage 33 in accordance with the pressure value of the suction chamber 20, and a rod protruding from its tip engages with the ball 31.

Suction ports 3 are provided on both side peripheral walls of the cam ring 8.
5 and 35 are bored, and these discharge ports 3
5 and 35, the discharge chamber 36 and the compression chamber 15 in the case 2 are connected to each other. These discharge ports 35,
35 is provided with a discharge valve 37 and a discharge valve stop 38, respectively.

(Operation) Next, the operation of the vane compressor according to the first embodiment of the present invention configured as described above will be explained.

First, the general operation of this type of vane compressor will be explained. When the rotor 11 rotates clockwise in FIG. 5 as the rotating shaft 12 rotates in relation to the engine of the vehicle, the vanes 17 protrude radially from the vane grooves 16 due to the pressure in the back pressure chamber 18 and the centrifugal force. The distal end surface rotates while slidingly contacting the inner peripheral surface of the cam ring 8, and a heat medium is introduced into the compression chamber 15 through the suction port 6, the suction chamber 20, and the suction port 19 during the suction stroke in which the volume of the compression chamber 15 is expanded. Gas is sucked in and compressed in a compression stroke to reduce the volume of the compression chamber 15, and in a discharge stroke at the end of the compression stroke, the compressed gas is sequentially passed through the discharge port 35, discharge valve 37, discharge chamber 36, and discharge port 5. It is supplied to a heat exchange circuit of an air conditioner (not shown) via the air conditioner.

The above operations are repeated, generally resulting in a full operating state where the discharge capacity is maximized and the maximum capacity is demonstrated.

By the way, when the full operating state continues to progress to such an extent that the room temperature becomes supercooled, for example, the pressure of the gas introduced into the suction chamber 20 through the suction port 6 decreases. Furthermore, the gas pressure within the suction chamber 20 is in a low state at the beginning of the operation.

Therefore, the vane compressor according to the present invention operates as follows. That is, when the gas pressure in the suction chamber 20 falls below a predetermined value (for example, 2 kg/cm ² ), the bellows 34
expands and pushes the ball 31 into the valve chamber against the spring force of the coil spring 30, opening the valve seat and communicating the two communicating passages 32, 33. the result,
The back pressure chamber 18 communicates with the suction chamber 20, and the back pressure decreases toward the suction gas pressure. Then, the piston valve 22
moves backward to reduce the back pressure receiving chamber 27 by the spring force of the corrugated leaf spring 26 when the pressure in the back pressure receiving chamber 27 becomes lower than the spring force of the corrugated leaf spring 26,
The port valve 25 opens the bypass port 21 (the state shown at the bottom in FIG. 1). As a result, the start timing of the compression stroke is different from when the vane 1 is in full operation.
7 passes through the bypass port 21, the delay is changed and the discharge capacity is reduced to a partial operating state.

Next, when the gas pressure in the suction chamber 20 increases and exceeds the predetermined value, the bellows 34 contracts and the pressing force against the ball 31 disappears.
comes into contact with the valve seat due to the spring force of the coil spring 30, cutting off communication between the communication passages 32 and 33, and as a result, the pressure in the back pressure chamber 18 increases. When the back pressure increases and the pressure in the back pressure receiving chamber 27 exceeds the spring force of the corrugated plate spring 26, the back pressure receiving chamber 27 expands against the spring force. It is urged forward in the direction of closing. When the bypass port 21 is closed, the start timing of the compression stroke returns to the original timing defined by the suction port 19 (the state shown in the upper part of FIG. 1).

At the beginning of operation, the gas pressure in the suction chamber 20 is originally low, so the bypass port 21
will start operating in an open state from the beginning. Therefore, the impact at the time of starting is alleviated and starting starts smoothly.

Then, the partial operating state and the full operating state are automatically repeated alternately. During partial operation, part of the discharged gas is discharged from the bypass port 21 to the suction chamber 20 side, as shown by the arrow in FIG.
The capacity of the compressor is reduced. As a result, the optimum air conditioning state is obtained by repeating the partial operation state and the full operation state.

In the vane type compressor according to the first embodiment described above, the ball valve 29 is driven to open and close by the bellows 34, but the bellows 34
Instead, it can be constructed of other suitable pressure-responsive bodies such as a diaphragm.

Alternatively, as shown in FIG. 6, the ball valve 71 may be composed only of a ball 72, a solenoid 73 for pressing and releasing the ball 72 may be provided, and the solenoid 73 may be controlled by a control device 74. That is, the control device 74 controls the rotor 11 at room temperature (Temp.).
The gas pressure in the suction chamber 20 is calculated according to the rotation speed (rpm) and other operating parameters (PRAM.), and if the gas pressure is less than the predetermined value, the solenoid 73 is excited, and If the value is above a predetermined value, the solenoid 73 is configured to be demagnetized. The solenoid 73 includes an electromagnet 75 and an armature 77 that is biased in a direction to press the ball 72 by a coil spring 76. When the electromagnet 75 is demagnetized, the armature 77
When the electromagnet 75 is excited, the armature 7
7 is attracted against the spring force of a coil spring 76 to separate the ball 72 from its valve seat.

Next, FIGS. 7 to 10 show a vane type compressor according to a second embodiment of the present invention. Note that the first
Components that are the same as those in the embodiment are denoted by the same reference numerals, and explanations thereof will be omitted.

In this second embodiment, the bypass port 2
A slider 81 serves as an opening/closing means for opening and closing 1 and 21.
is provided. This slider 81 is disposed on the side wall surface of the front side block 9 on the side of the compression chamber 15 so as to be able to move up and down.
is formed, and the other end of the slider 81 is constantly pressed and biased by a coil spring 82, as shown in FIG.

Further, as shown in FIG. 10, the front side block 9 has a first ball valve 29 as an on-off valve.
A bellows 34 for controlling the opening and closing of the ball valve 29 is provided in the same manner as in the first embodiment.

(Operation) The operation of the vane compressor according to the second embodiment of the present invention configured as above will be explained.

When the gas pressure in the suction chamber 20 is below the predetermined value, the ball valve 29 opens and the pressure in the back pressure chamber 18 decreases toward the gas pressure in the suction chamber 20. When the pressure in the back pressure receiving chamber 82 becomes lower than the spring force of the coil spring 83, the slider 81 is biased by the coil spring 83 and moves downward toward the rotor shaft 12, so that the slider 81 is bypassed as shown on the lower side in FIGS. 7 and 9. Port 21 is opened. As a result, the device enters a partially operating state, similar to the first embodiment.

Further, when the intake gas pressure becomes equal to or higher than the predetermined value,
The ball valve 29 closes and the pressure in the back pressure chamber 18 increases. The pressure in the back pressure receiving chamber 82 expands and the slider 8
1 toward the coil spring 83 side, and the bypass port 21 is closed as shown in the upper side in FIGS. 7 and 9. As a result, the device becomes fully operational as in the first embodiment.

Next, FIG. 11 shows a vane type compressor according to a third embodiment of the present invention.

In this third embodiment, the bypass port 2
The same slider 83 as in the second embodiment is used as the opening/closing means for opening and closing the front side block 9, but as a method for controlling back pressure, the back pressure receiving chamber 8 of the front side block 9 is
2 and the suction chamber 20, and a ball valve 92 that controls the opening and closing of the communication path 91. The ball valve 92 is driven and controlled by a solenoid 93, and the solenoid 93 performs control as illustrated in FIG. It is controlled by a device 74.

Solenoid 93 includes electromagnet 94 and armature 95
When the electromagnet 94 is demagnetized, the armature 95 is biased by the leaf spring 96 and the ball valve 92
When the electromagnet 94 is energized, the armature 95 is attracted by the electromagnet 94 and opens the ball valve 92.

As a result, the same effect as in the second embodiment can be obtained.

In each of the above embodiments, the vane back pressure is controlled, but the discharge pressure may be controlled more actively.

(Effects of the Invention) As described in detail above, the vane type compressor of the present invention has a bypass port that is formed downstream of the suction port of the side block in which the suction port is provided and communicates the suction chamber and the compression chamber, and a vane base. has a back pressure receiving chamber into which back pressure applied to the back pressure is introduced, and is biased in a direction to close the bypass port by the pressure of the back pressure receiving chamber, and is biased in a direction to open the bypass port by a spring force. an opening/closing means that is energized;
an on-off valve that opens and closes a communication path that communicates the back-pressure receiving chamber with the suction chamber; and an on-off valve that opens and closes the on-off valve when the pressure in the suction chamber is below a predetermined value, thereby reducing the pressure in the back pressure receiving chamber. and control means for increasing the pressure in the back pressure receiving chamber to above the spring force by lowering the pressure to below the spring force and closing the on-off valve when the pressure in the suction chamber is above the predetermined value. As a result, it is possible to realize a variable capacity vane type compressor that can be switched stepwise and alternately between a full operating state and a partial operating state with a simple structure that is easy to manufacture.

Furthermore, since the back pressure control method reduces the back pressure of the vane during partial operation, the sliding resistance between the vane and the cam ring is reduced. Therefore, durability is improved and power loss is reduced.

Furthermore, since the engine is in partial operation at the start of operation, the shock at startup is alleviated.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a vane type compressor according to a first embodiment of the present invention, FIG. 2 is a perspective view showing essential parts of the present invention, and FIG. 3 is taken along line A-A in FIG. 1. 4 is a sectional view taken along the line C-C in FIG. 3, FIG. 5 is a sectional view taken along the line B-B in FIG. 1, and FIG. 6 is a sectional view of the control means shown in FIG. 4. FIG. 7 is a sectional view showing a vane type compressor according to a second embodiment of the present invention, and FIG. 8 is a partial sectional view showing another embodiment.
9 is a sectional view taken along line A, FIG. 9 is a sectional view taken along line BB in FIG. 7, FIG. 10 is a sectional view taken along line E-E in FIG. 8, and FIG. 11 is a sectional view taken along line EE in FIG. It is a sectional view showing a vane type compressor concerning an example. 8... Cam ring, 9... Front side block, 11... Rotor, 12... Rotating shaft, 15... Compression chamber, 16... Vane groove, 17... Vane, 18... Back pressure chamber, 19... Suction port, 20... Suction chamber, 21 ... Bypass port, 22 ... Piston valve, 26 ... Corrugated leaf spring, 27, 82 ... Back pressure receiving chamber, 29, 71, 92
...Ball valve, 28, 32, 33, 91...Communication path,
34...Bellows, 73,93...Solenoid, 74
…Control device.

Claims (1)

[Scope of Claims] 1. A cam ring whose both sides are closed with side blocks, a rotor rotatably disposed within the cam ring, and a plurality of vanes slidably fitted into vane grooves of the rotor. In a vane type compressor, the fluid introduced from the suction chamber into the compression chamber via the suction port is compressed by a change in the volume of the compression chamber defined by the side block, rotor, and vane. , a bypass port formed on the downstream side of the suction port of the one side block where the suction port is provided and communicating the suction chamber and the compression chamber; and a back pressure into which the back pressure applied to the vane base is introduced. an opening/closing means having a pressure receiving chamber and biased in a direction to close the bypass port by the pressure of the back pressure receiving chamber and biased in a direction to open the bypass port by a spring force; and the back pressure receiving pressure. an on-off valve that opens and closes a communication path that communicates between the chamber and the suction chamber; and when the pressure in the suction chamber is below a predetermined value, the on-off valve is opened to reduce the pressure in the back pressure receiving chamber to below the spring force. and control means for raising the pressure in the back pressure receiving chamber to a level higher than the spring force by closing the on-off valve when the pressure in the suction chamber is higher than the predetermined value. Vane type compressor. 2. The opening/closing means is a piston valve that reciprocates in the axial direction of the rotor on the suction chamber side, and one end of which forms a valve body opens and closes the bypass port, and the back pressure receiving chamber is on the other end side of the piston valve. Claim 1, wherein the piston valve is formed at a portion that slides into contact with the bottom surface of the suction chamber, and the spring member is disposed on the one end side of the piston valve.
Vane type compressor as described in section. 3. The opening/closing means is a slider disposed on a side surface of the one side block facing the compression chamber so as to be movable up and down, and which opens the bypass port when it moves downward toward the rotor and closes the bypass port when it moves upward. Claim 1, wherein the back pressure receiving chamber is formed on the lower moving end side of the slider, and the spring material is arranged on the upper moving end side of the slider. Vane type compressor as described. 4. The vane type compressor according to claim 1, wherein the control means comprises a pressure-responsive body that opens and closes the on-off valve in response to the pressure in the suction chamber. 5. The control means comprises a solenoid that opens and closes the on-off valve, and a control device that controls excitation and demagnetization of the solenoid in accordance with a detected pressure value in the suction chamber. 1
Vane type compressor as described in section.